In metal working it is sometimes desirable to provide lubrication to an interface between a metal working tool, such as a drill or a lathe, and a working piece. One type of lubrication process is known as “wet machining” and includes flooding an interface between a metal working tool and a workpiece with a liquid lubricant, such as oil or coolant. This type of lubrication process results in lubricant being entrained in the air surrounding the interface. Another type of lubrication process is known as “dry machining,” and includes the supply of a mixture or mist of oil suspended in air or a mixture or mist of a liquid coolant suspended in air directed to the tool/workpiece interface. Exposure, in a working environment, to the airborne lubricant resulting from wet machining or dry machining, however, may present health hazards. In this regard, agencies such as the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA) have developed standards that limit the concentration of airborne liquid lubricants such as oil or coolant, to which a person in an industrial environment may be exposed, to about 5 mg/m3. To this end, it is known to place the lubricated interface between the metal working tool and the workpiece within an enclosure or “doghouse.”
Once the liquid lubricant-containing mist or mixture has been used and/or a metal working project has been completed, the residual mixture of air and airborne lubricant in the doghouse must be processed so that the lubricant (e.g., oil or coolant) concentration can be reduced to an acceptable level and thus made to comply with the required standards set by NIOSH and OSHA. To this end, conventional systems include directing a stream of the lubricating mixture leaving the doghouse through a device having disposable media such as filters or cartridges. A challenge with such devices, however, is the required timely replacement of the disposable media. More specifically, if such media are not replaced when required, the efficacy of the device in reducing the lubricant content is affected, resulting in air flowing into the machine shop or similar space where the doghouse is located that has a higher-than-desired lubricant content.
Moreover, the disposal of consumable, lubricant-filled media from such devices is inconvenient, insofar as the disposal of such media may require compliance with pollution-control procedures. Finally, operation of such devices results in ongoing operational costs. For example, there are costs directly associated with the required purchase of replacement media (e.g., filters, cartridges), costs associated with the downtime and labor required to replace such media, and costs associated with replacing the lubricant (e.g., oil, liquid coolant) used up by the supply of the lubricating mist or mixture.
It would be desirable, accordingly, to provide an apparatus and related methods that address these and other problems associated with conventional devices designed for such purpose.